Valved tool for bleeding brake cylinders



Sept. 23, 1952 c. J. LEGl-:RsKl

vALvED Toor, FOR BLEEDING BRAKE CYLINDERS Filed May 27, 1946 z5 Z5 Z7 26 Z0 2/ /9 ATTORNEY Patented Sept. 23, 1952 vAnVED mooLJFoR BLEEnma-Bm um CYLINDERS y f inventio'nrelatesto' a tool' for; bleedingAA brake cylinders and" moreparticularly' tola tool fr't'his"purposegtiiat i's simple` in` constru'etion' and" which may be utlizedf'` to bleed'vl brakev eylin#` ders' providedwith blee'der. screws oftwo difier-` ent standard" sizes. f

.In hydraulicV brake systems' for automotive vehicles; it is Well known that the 'presence of"l air? in the' brake" operating cylinder prevents eicient'operation of" the brakes; T-enab'le the air" to be expelled from the system, itjis the" practice at the present time to provide each brake .cylinder with a bleeder. screw; Sucli` bleed'er scr'ewsfare usually of" t'wo standrd si'zes one. sizej beingstandard* for most` cars,vr while' thel other* size i'sr standard for"t1"ucki-7ffandaii'plaueslv although ir'rtsom'e 'cars' thef bleder;screws are', of tii'etsanre sizel astri-e' lleeder: screws on' airplanes", anjdtrucks'. Y j

l'rservicing brakes, itis'tlie"practieetorst openthe" bleeder screw? The mechanic? alieni pumpsrthe foot pedal` to` expel". tlie air from the? brake' cylinder and* his' helperT then 'tightens the bleed'er/screw' to' preventtlie? refentr'ance` of air? additional brake fluidi' m'ay'th'envk b'esupplied if 2 desired1 to themaster-feylinder1" Sucli practice: however; `requires theservie of twwmen lie?v causeif the Y mechanic" releases: the" pressure ony thee b'ralrfe*y pedallhv andthen closestlie*blee'der" screw; airy Willreentr'tlie-bralce cyliideribefre'f lelia's" anvopportunityto' close `the-b'leaderscrew:

It'lissanmbj ectjof 'tliie'qnresent'inventionY toeproj vide* anvimproved tool by means-"off wliich'" the' b'alesemawbabledeliy one'-mechanic:l

' Arrvotlier-I object off' my@ inventiorris toi providef a comparatively* small tool? for`v4 bleedingbrake4` Fig'. 4" isLa' crossjY sectional'view' ofi' ai modificar-f tienioffmyimprove'dtooi'; and

' mayjbe utilized in conjunction" witlim fiimproifed plied'from a master'cylinder; Anot shown, through' a conduit 8. In' operation" when t pressure is" ap# plied.- to. the' foot.' pedal; liquid' is forced lintojthe cylinder 1 and moves pistons; 54 and.' 6j outwardly` to: actuate" the brake' shoes' which' are'y returned" to. tlieir normal" plositicms by the' force of'springs 4" and`5 when thepressure' upon the' pistons is' released '-Airyliovvever, has'tlre tendency to accumulate" inV the" brake: cylinderj which, b'eingf compressible. lias the tendencyto impair' the4v eli'ciency (Jftlilff'l ,y bralesgand during: servicing` of." the'y brakes; itfA i`s-tlerefore desirable. to' bleed the' airfrom'jtliev lrake cylinders.V y

,l For thifs'purpose', each' brake'. cylinder hasfan internallythreaded opening 'providedwith'avalv V seat Storeceive an externally threaded bleeder' screw |I),1theV inner portion oiwhich is b'evelled,

as; indicatedlby the numerall Il: to" engage'-tlie valve seat y9 andy 'close the' opening wl'enscrew l0 is tightened'. Bleed'er" screw l'isalso" providd' with' a' diametrically extending`openin'g |21". Wliilil communicates with the brake' cylinder" when4 screw Illr isloosened; an internal bore" I34r whicncommunicates with the opening; .an'd' anI enlarged counterb'ore I4 which is'intern'ally' 45 threaded; In: normal operation, screw"V l1", is"

loosened" and'l one yend of a metal" nippley Il'rfon. a hose' |6`istlireadedto bleederscrevv' H) toconii duet` airfiom tliebra'ke cylinde'riwhen' thepedal7 is pumped' during servicing" of'v the brakes.. Itf' ofFigi' 1", -loolngiwtliefdirection'offthe arrows;

bleeder screw when the internal threads of the bleeder screw are of a larger standard size.

In accordance with my invention, I have provided an improved tool which may be connected to either end of hose I6 or which may be connected directly to the internal threads of bleeder screws of two standard sizes.

One form of my improved ltool `is' shown in Figs. 1 and 3 of the drawing and comprises a hollow body I9 having a reduced portion provided with external threads 20, an internal bore 2| forming part of a central chamber,` a'valve seat 22, and an internal bore 23 of less diameter than bore 2I which communicates Vwith, the central chamber and an enlargedy counterbore 24 provided with internal threads. The other hol-v 4 threaded bleeder screws of two different standard sizes.

Another modification of my improved tool is shown in Fig. 4 of the drawing which is similar to that shown in Fig. 3 with the exception that instead of providing internally threaded bores 24 and30, externally threaded nipples 35 and 36 are provided, thefnipple 35'being of a's'ize to be threaded into the internal bore of a small standard size bleeder screw, such as shown in Fig. 2, and nipple 38 being of a size to be threaded into the internally threaded nipple of a bleeder screw nally threaded to receive the nipple I5 of hose an internally threaded portion 26 which'engages the external threads "on the portion 2I to form a smooth outer periphery and with an internal bore 21 arranged in alignment with bore 2| to form a central chamber. Portion 25k is also provided with a valve seat 28 which communicates through a bore 29v of small diameter with an' enlarged counterbore 30 provided with internal threads. As illustrated in Fig. 3, valve parts 3| and 32, which as shown are preferably of the balltype, engage valve seats 22 and 28, respectively, and are held in seating engagement by resilient means, such as a spring 33, arranged in the central chamber. As shown, the portion is provided :with an aperture' 34 through which airtand any liquid which is bled fromthe brake cylinders may be removed.

AIn .utilizing my improved tool for bleeding.

brake cylinders, the bleeder screw I8 may be loosened in thevus'ual manner and nipple I5, which vis attached to one end of a hose I 6 is threadedfinto the bleeder screw as shown in Fig.'

2. The nipple I1 on the other end of hose IBis,

then threaded into the internal threads 30 of my improved tool and when the mechanic pumps the brake pedal, air and entrained liquid are forced through the hose I6 and the pressure of the air and liquid unseat valve 32 which permits the liquid and air to be expelled through opening 34. When the mechanic releases the brake pedal,

however, spring 33 forces valve part 32 against` valve seat 28, thus preventing the reentrance of air into the brake cylinder. The mechanicV then tightens screw IU to retain the liquid in the brake.

cylinder and prevent the reentrance' of air. The hose may then be removed from the bleeder screw. j

It will be particularly notedl that the threaded bore 30 is larger than threaded bore `24, and in fabricating my improved tool, bore 30 is formed to correspond to the internally threaded bore of a bleeder screw of` one standard size while bore 24 is formed to correspond to the internally threaded bore of a bleeder screw of a smaller standard size. When nipple I5 is threaded into the internal bore of a bleeder screw of a small standard size as shown in Fig. 2, nipple I'I at the opposite end of the hose may be threaded into borev 30. When the bleeder screw has an internally threaded bore of a larger size, such as'is used inftrucks, airplanes, and some cars, the nipple I I of the hose may be threaded into the internal borel of the bleeder screw and the nipple I5 into the internally threaded `bore 24 of my improvedtool and the brake cylinder may then .be bledin the manner previously specified. One of my improved tools may therefore beutilized to bleed brake cylinders -provided with internally I8 so that liquid expelled during the pumping of the brake may be conducted away from the vehicle. The other parts of the tool are similar to those shown inFig. 3 and consequently have been designated by the same reference numerals.

`It will be noted that my improved toolis sim'fy ple ink construction vand the parts maybe fabricated andassembled in an easy manner by un' skilled workmen and for this purpose, bodies I9` and 25 may be knurled as indicated by the numerals 38 and 39. To clean the tool, parts I9 and 25 may be unthreaded which enables balls 3I and 32 and spring 33 toy be removed, and after the parts have been cleaned, they may be yreadily reassembled for use.

What I claim is:

1. A small portable tool for use inA servicing brakes, said tool being composed of rst and second interfitting parts which may be removed' from eachother to enable the interior portionv of the tool to be cleaned, each of Said tool partshaving a cylindrical bore and an outer cylindrical surface of the same size as theothertool part and the cylindricalsurfaceof eachofsaid parts being free from `external projections so that the tool may be readily grasped by the ngers of VanI operator, the .cylindrical bore in each of said tool parts being in alignment with each other to forma central cylindrical chamber when the tool parts, are in intertting engagement with each other,- and each of said tool parts having a second bore.

communicating with, the central chamber and extending from the central chamber-to itsvfree end, eachof said second bores being of less diam-g eter thanthe central chamber and each-being of the samediameter at theirentrance to the central chamber and each of said tool parts having a valve seat'arranged between its second bore and the central chamber, a valve part of less ldi ameter than the central chamber arranged to` being of a size larger than the other 'tting -so' that said tool may be I itted to couplings of two diierent sizes, and one of said tool parts'beingA provided with an opening leading fromjthe central chamber to the externalsurface-of said tool.-

which terminates ush therewith for permitting the liquid and-entrained air'enteringl the centralI chamber through one of said second bores to force one of the valve parts from its seat to enter the central chamber and to be drained from the central chamber of said tool.

2. A small portable tool for use in servicing brakes, said tool being composed of first and second intertting parts which are removable from each other to enable the interior portion of the tool to be cleaned, each of said tool parts having a cylindrical bore and an outer cylindrical surface of the same size as the other part and the cylindrical surface of each of said parts being free from external projections throughout their entire length so that the tool may be readily grasped by the ngers of an operator, the cylindrical bore in each of said tool parts being in alignment with each other to form a central cylindrical chamber when the tool parts are in intertting engagement with each other, and each of said tool parts having a second bore communicating with the central chamber and extending from the central chamber to its free end, each of which is of less diameter than the central chamber throughout its length and each of said bores being enlarged at a spaced distance from the central chamber and one being provided with internal threads over its enlarged part to engage a threaded tting of a brake cylinder of one size and the other` being enlarged at a spaced distance from the central chamber and being provided with internal threads of a larger size than the internal threads in the other bore to receive a threaded fitting of a brake cylinder of a diierent size, a Valve part of less diameter than the central chamber arranged to engage one of said seats and a valve part of less diameter than the central chamber arranged to engage the other seat, a spring of less diameter than the central chamber arranged in the central chamber and having one of its end engaging one of said valve parts and its other end engaging the other valve part and normally maintaining both of said valve parts in engagement with its respective seat, and one of said tool parts `being provided with an opening leading from the central chamber to the external surface of said tool which terminates flush therewith for permitting liquid and entrained air entering the central chamber through one of said second bores to force one of the valve parts from its seat to enter the central chamber and to be drained from the central chamber of said tool.

3. A small portable tool for use in servicing brakes, said tool being composed of rst and second interfltting parts which are removable from each other to enable the interior portion of the tool to be cleaned, each of said tool parts having a cylindrical bore and an outer cylindrical surface of the same size as the other tool part, and

the cylindrical surface of each of said parts being free from external projections so that the tool may be readily grasped by the i'lngers of an operator, the cylindrical bore in each of said tool parts being in alignment with each other to form a central cylindrical chamber when the tool parts are in intertting engagement with each other, and each of said tool parts having a second bore communicating with the central chamber and extending from the central chamber to its free end, each of which second bores is of less diameter than the central chamber and each being of the same diameter throughout its length and each of said tool parts having a valve seat between its second bore and the central chamber, said firsttool part having an externally threaded nipple through which its second bore extends and the second tool part being provided with an externally threaded nipple through which its second bore extends and one of the externally threaded nipples being larger than the other nipl ple so that it may be secured to the threaded tting of a brake cylinder having a larger size than the rst nipple, thereby enabling brake cylinders of two different sizes to be serviced by a single tool, a valve part of less diameter than the central chamber arranged to engage one of said valve seats and a valve part of less diameter than the central chamber to engage the other valve seat, a spring of less diameter than the central chamber arranged in the central chamber having one end engaging one of said Valve parts and its other end engaging the other valve part and normally maintaining both of said valve parts in engagement with its respective seat, and one of said tool parts being provided with a threaded opening leading from the central chamber to the external surface of said tool which terminates ilush therewith to permit a hose to be connected thereto to drain away liquid and entrained air from the central chamber which enters the central chamber through one of said tool parts against the force of said spring.

CHARLES J. LEGERSKI.

REFERENCES CTED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 12,966y Stoddart May 29, 1855 1,582,928 Hoag May 4, 1926 1,673,247 Keith June 12, 1928 1,958,155 Watkins May 8, 1934 2,009,433 Carroll July 30', 1935 2,069,606 Gary Feb. 2, 1937 2,138,988 Thomas Dec. 6, 1938 2,360,839 Barksdale Oct. 24, 1944 

